I can believe it, and there's no reason to skip on the previous games if that's what OP wants to do.
But MGS4 was my first MGS and it was one the highlights of last gen for me, without reservations. If anything, I think people who were attached to the characters and storylines over a long period of time seemed to have a negative reaction to MGS4 so I would hope people wouldn't set OP up to play the previous games just to join them in misery with MGS4. Not when OP could just enjoy it for the cheesy, philosophical, sexist, cloned limb super robot ninja awesome Tom Clancy romance novel fart-filled experience that it is.